DIY Homeowners: How do you seal ductwork?

[Why Not?]

So I had my annual A/C check today and the guy says my duct work is leaking. I'm a bit skeptical of all sales guys in the home improvement industry and the $2,300.00 price tag seems a bit high. What about you guys? Anyone have experience with sealing their own duct work? Thanks in advance.

[Simply Red]

your mom

[Rasputin]

You can pay me the $2,300.00 and I will tell you all I know about duct work.

[Why Not?]

You can pay me the $2,300.00 and I will tell you all I know about duct work.

2 for 2 so far. And to think just a fee weeks ago people were saying CP had lost it's burst

[Simply Red]

2 for 2 so far. And to think just a few weeks ago people were saying CP had lost it's burst



LMAO

[srvy]

Why not seal the leak?

[srvy]

is it condensation from A/C ducting?

[Why Not?]

is it condensation from A/C ducting?

No and I should have been more clear, it's air leaking not condensation or moisture.

[srvy]

Oh ok. And they know this how is it exposed?

[Rain Man]

I'm skeptical. I have a 100 year-old house and no one has ever told me this.

Plus, if a duct is leaky, it's still dumping its heat and cooling in the house. It's just happening at a different place. If you're comfortable now and don't have any big hot or cold spots, why would you care? It's not necessarily wasted energy as long as it's not dumping straight out an exterior wall or something.

As a side story, I suspect we had a leaky duct at one point below our dining room floor. We never noticed it until we finally figured out why our cat liked to lie there in the winter. There was a spot on the dining room floor just above a duct that was always really nice and warm, and that was his spot. Unfortunately, after a remodel it ended up being right in the traffic path of a new doorway, but he didn't mind and we just had to step carefully around him. Eventually we replaced the furnace and also replaced that duct, and he lost his winter spa spot.

[srvy]

I would get a 5 dollar roll of duct tape and go to work.

[Why Not?]

I'm skeptical. I have a 100 year-old house and no one has ever told me this.

Plus, if a duct is leaky, it's still dumping its heat and cooling in the house. It's just happening at a different place. If you're comfortable now and don't have any big hot or cold spots, why would you care? It's not necessarily wasted energy as long as it's not dumping straight out an exterior wall or something.

As a side story, I suspect we had a leaky duct at one point below our dining room floor. We never noticed it until we finally figured out why our cat liked to lie there in the winter. There was a spot on the dining room floor just above a duct that was always really nice and warm, and that was his spot. Unfortunately, after a remodel it ended up being right in the traffic path of a new doorway, but he didn't mind and we just had to step carefully around him. Eventually we replaced the furnace and also replaced that duct, and he lost his winter spa spot.

That's a great point about the air still going into the house.

Funny story as well. Thanks

[Why Not?]

I would get a 5 dollar roll of duct tape and go to work.

Yeah that's kinda what I'm thinking

[HoneyBadger]

Had my AC replaced last year. One company said I needed to spend about the same to fix my leaks. Second company came in and said they were just after the money and not to worry about it as long as I don't run my air 24/7.

[HoneyBadger]

Or you could use gum.That would fix the leaks.

[Baby Lee]

<iframe width="560" height="315" src="//www.youtube.com/embed/OFhwhKsbOJM" frameborder="0" allowfullscreen></iframe>

[Moon§hiner]

If the ductwork is in the attic, seal and wrap with foil insulated material. If its in the basement, seal with duct tape where you feel excessive air leaking. usually it's poor sealing at the take offs that lead to runs.

[cosmo20002]

Seems like they make a tape for ducts.
I can't remember what it's called though.

[Abba-Dabba]

.

[BigMeatballDave]

Seems like they make a tape for ducts.
I can't remember what it's called though.

The duct tape you're thinking about doesn't work well for that.

[Coochie liquor]

If the ductwork is in the attic, seal and wrap with foil insulated material. If its in the basement, seal with duct tape where you feel excessive air leaking. usually it's poor sealing at the take offs that lead to runs.

This!

[FlaChief58]

Silver duct tape and mastic will fix you right up

[beach tribe]

Duct Tape
Problem solved.

[Bwana]

Has anyone brought up duct tape? :)

[Jimmya]

Wow, that is a steep price. I agree with all the others, tape it.

[BigMeatballDave]

I've always heard the foil tape is much better than regular duct tape.

[Why Not?]

Yeah, the online research I did led me to learn that duct tape actually doesn't work real well on ducts. Who knew? Thanks for all the feedback.

[Why Not?]

Silver duct tape and mastic will fix you right up

I've heard mastic is great so I think gonna get some

[Why Not?]

Had my AC replaced last year. One company said I needed to spend about the same to fix my leaks. Second company came in and said they were just after the money and not to worry about it as long as I don't run my air 24/7.

Yeah I think they were after the $. Looks like I can do it myself if at all plus the service tech looked weirdly like Mike Moustakas making me even more skeptical of him

[Halfcan]

Duct tape

[kepp]

Seems like they make a tape for ducts.
I can't remember what it's called though.

LMAO

[cosmo20002]

The duct tape you're thinking about doesn't work well for that.

Wow, what a scam.
All these years you hear about how duct tape can fix anything and it turns out the one thing it doesn't work on is fucking ducts.

[Why Not?]

Wow, what a scam.
All these years you hear about how duct tape can fix anything and it turns out the one thing it doesn't work on is ****ing ducts.

I know, right?

[BigMeatballDave]

Wow, what a scam.
All these years you hear about how duct tape can fix anything and it turns out the one thing it doesn't work on is fucking ducts.

It's good for holding stuff together. It's just not a good sealant. Usage on ductwork
The product now commonly called duct tape should not be confused with special tapes actually designed for sealing heating and ventilation ducts. To provide laboratory data about which sealants and tapes last, and which are likely to fail, research was conducted at Lawrence Berkeley National Laboratory Environmental Energy Technologies Division. Their major conclusion was that one should not use common duct tape to seal ducts (they had defined duct tape as any fabric-based tape with rubber adhesive). The testing done shows that under challenging but realistic conditions, common duct tapes become brittle and may fail.[28][29]

Common duct tape carries no safety certifications such as UL or Proposition 65, which means the tape may burn violently, producing toxic smoke; it may cause ingestion and contact toxicity; it can have irregular mechanical strength; and its adhesive may have low life expectancy. Its use in ducts has been prohibited by the state of California[30] and by building codes in most other places in the US. However, higher quality metallized and aluminum tapes used by professionals for sealing ducts are still often called "duck/duct tapes".

[A Salt Weapon]

Foil tape is better than duct tape.

[Mr. Laz]

ducts are made to fit loose so that they can expand and contract with temp change


I think all ducts leak some


they make aluminum tape for sealing ducts


finding and getting to the BIG leaks is the problem

[CoMoChief]

Holy shit duct work should never cost $2300.00 unless it's a total repair job.

Just find out where it's leaking and duct tape the shit out of it.

that's what "DUCT TAPE" is for... :)

[BigMeatballDave]

Holy shit duct work should never cost $2300.00 unless it's a total repair job.

Just find out where it's leaking and duct tape the shit out of it.

that's what "DUCT TAPE" is for... :)

Standard grey duct tape is not a good remedy here.

Doesn't Bugeater do HVAC? He'll know.

[salame]

http://doctoratclick.com/blog/assets/2nd-opinion-T4H.png

[mikeyis4dcats.]

http://www.energystar.gov/ia/products/heat_cool/ducts/DuctSealingBrochure04.pdf?7938-5d69

[Eureka]

I would get a 5 dollar roll of duct tape and go to work.

Use a high quality duct tape that's ment for ducting. Is it flex duct or ridged pipe? Replace flex duct where necassary and tape pipe where it joins together.

I haven't seen the setup but I assume 2300 is to replace all the ducting.

[displacedinMN]

The best is the aluminum foil tape. Very thin-very sticky.

http://www.homedepot.com/p/Nashua-Tape-322-1-57-64-in-x-50-yds-Aluminum-Foil-Tape-3220020500/100030120

[Eureka]

The best is the aluminum foil tape. Very thin-very sticky.

http://www.homedepot.com/p/Nashua-Tape-322-1-57-64-in-x-50-yds-Aluminum-Foil-Tape-3220020500/100030120

That stuff is overkill. Works good on plenums but is not really needed. Depending on the jobsite that alum tape can take a long time to use vs duct tape.

[Mr. Laz]

Black & Decker TLD100 Thermal Leak Detector
by Black & Decker
List Price: $52.80
Price: $27.23 & FREE Shipping on orders over $35.

http://ecx.images-amazon.com/images/I/61EDf1k22rL._SL1500_.jpg

http://www.amazon.com/Black-Decker-TLD100-Thermal-Detector/dp/B0044R87BE

[DTLB58]

Oh I don't know, duct tape. LMAO

[Abba-Dabba]

That stuff is overkill. Works good on plenums but is not really needed. Depending on the jobsite that alum tape can take a long time to use vs duct tape.

Not is it only overkill. It really wouldn't be a one and done fix. There are going to be some areas aluminum tape just won't cut it. Metallized polypro tape would have the proper glue needed and would work for the smallest of patches, and be able to fill in larger patches with a few strips for a quick fix.

[kcpasco]

You use duct sealant. You can buy it in a tube or a 1 gallon bucket which you put it on with a paint brush.
But if it's holes in the flex then you need to replace the flex.
I am a Sheet Metal Worker.

[Why Not?]

You use duct sealant. You can buy it in a tube or a 1 gallon bucket which you put it on with a paint brush.
But if it's holes in the flex then you need to replace the flex.
I am a Sheet Metal Worker.

Thanks. Do I just climb around inside the roof/ceilings and make my way to all the ducts?

[kcpasco]

Thanks. Do I just climb around inside the roof/ceilings and make my way to all the ducts?

Are your ducts in an attic or in the crawlspace? Either way yes you are gonna have to get to them. And since this is a house I am gonna just assume most of your ducts are flex and the only place that is metal that could be leaking is on the plenum.

Flex is actually pretty simple to replace. All you need is a knife a pair of wire cutters and some panduit straps and a panduit gun. Just make sure you leave enough slack in the flex before you cut it so it's not stretched to tight.

[Why Not?]

Are your ducts in an attic or in the crawlspace? Either way yes you are gonna have to get to them. And since this is a house I am gonna just assume most of your ducts are flex and the only place that is metal that could be leaking is on the plenum.

Flex is actually pretty simple to replace. All you need is a knife a pair of wire cutters and some panduit straps and a panduit gun. Just make sure you leave enough slack in the flex before you cut it so it's not stretched to tight.

Attic

[kcpasco]

Well 2300 dollars seems like an awful lot for just going around and slapping some sealent on some ducts especially considering that the majority is gonna be flex. If I was you I would ask specifically what is leaking and needs to be either sealed or replaced.

But then again I am wondering how you got so many leaks in your duct. Finding a few leaks sure but 2300 hundred dollars worth would throw up a major red flag to me.

[kcpasco]

Oh and make sure you use either tape or sealant where the flex is connected to the takeoff or the boot. A lot of contractors skip doing that during construction.

[TimeForWasp]

heat = anti freeze

It's leaking antifreeze

[mikeyis4dcats.]

Are your ducts in an attic or in the crawlspace? Either way yes you are gonna have to get to them. And since this is a house I am gonna just assume most of your ducts are flex and the only place that is metal that could be leaking is on the plenum.

Flex is actually pretty simple to replace. All you need is a knife a pair of wire cutters and some panduit straps and a panduit gun. Just make sure you leave enough slack in the flex before you cut it so it's not stretched to tight.

depending on the location and age, the house very well could be all metal. Both of my houses have not has an inch of flex, built in 1947 and 1988.

[Why Not?]

depending on the location and age, the house very well could be all metal. Both of my houses have not has an inch of flex, built in 1947 and 1988.

Arizona and 1994

[kcpasco]

depending on the location and age, the house very well could be all metal. Both of my houses have not has an inch of flex, built in 1947 and 1988.

Ya that's true. But if that is the case then buy a gallon or 2 of sealant a couple paint brushes and go to work.
But odds are its gonna be insulated then you are gonna have to replace that also.

[Baby Lee]

You use duct sealant. You can buy it in a tube or a 1 gallon bucket which you put it on with a paint brush.
But if it's holes in the flex then you need to replace the flex.
I am a Sheet Metal Worker.

Any experience with the blown in epoxy sealant in the This Old House clip above?

Worth the money? It certainly lowered the losses precipitously.

[kcpasco]

Any experience with the blown in epoxy sealant in the This Old House clip above?

Worth the money? It certainly lowered the losses precipitously.

No I have never used it. But I do not have a lot of experience on the residential side, I have mainly worked on commercial jobs.

[Eureka]

Also remember rodents love to make there home inside flex duct. It's easy for them to chew a hole through the flex.

Hard pipe with bubble wrap will last the longest and is impenetrable for rodents.